Clean up module documentation (#36909)

* Clean up module documentation

This PR includes:
- Removal of `default: None` (and variations)
- Removal of `required: false`
- Fixing booleans and `type: bool` where required

* Fix remaining (new) validation issues

lib/ansible/modules/cloud/azure/azure_rm_containerregistry.py

@@ -27,7 +27,6 @@ options:
     name:
         description:
             - Name of the Container Registry.
-        default: null
         required: true
     state:
         description:
@@ -43,7 +42,8 @@ options:
     admin_user_enabled:
         description:
             - If enabled, you can use the registry name as username and admin user access key as password to docker login to your container registry.
-        default: false
+        type: bool
+        default: no
     sku:
         description:
             - Specifies the SKU to use. Currently can be either Basic, Standard or Premium.